Reduction of megakaryocyte-erythroid progenitors (MEPs, Lin−CD34+CD38+CD123-CD45RA−) can be observed on both high-risk and low-risk MDS, with a relatively greater reduction in low-risk MDS (Will et al., 2012; Pang et al., 2013), suggesting a differentiation block in the transition from CMPs to MEPs. This evidence concerns the gene CD38 and myelodysplastic syndrome.